Over the years, portable (or hand-held) game systems have been (and continue to be) very popular. Typically, these portable game systems include a hand-held game system housing a processing unit and associated hardware for running a game program, and include a display for displaying images of the game. The game program itself is typically contained in a game program memory such as, for example, a semiconductor memory (e.g., ROM, EPROM, etc.) that is part of a removable cartridge. By storing the game program in a removable cartridge, the user can conveniently and easily change the game being played by simply exchanging one cartridge with another, different cartridge containing a different game. Examples of portable game systems are the “Game Boy®” and “Game Boy® Color” products manufactured and sold by Nintendo Corporation, Ltd. Throughout this application, the “Game Boy” product is referred to as “DMG” and the “Color Game Boy” product is referred to as “CGB”.
FIGS. 1A, 1B and 1C show the CGB. The CGB displays game characters in color on a color liquid crystal display (LCD) 116 when a color-ready game cartridge 112 is selectively inserted into a game cartridge slot 118 (see FIG. 1C). FIG. 2 shows the external appearance of game cartridge 112. Color LCD 116 displays characters using a plurality of different colors if color-ready game cartridge 112 is inserted into the CGB. The CGB may also be configured to receive monochrome game cartridges (not shown) usable with the DMG and to display monochrome characters on LCD 116.
With reference to FIG. 3, the CGB includes color LCD 116 as described above. Color LCD 116 is formed as a dot matrix display and is driven by LCD drivers 122 and 124 to display color images on its screen. LCD driver 122 selectively drives, for example, the rows of the dot matrix display and LCD driver 124 selectively drives, for example, the columns of the dot matrix display. LCD drivers 122, 124 are supplied with color image signals from a color display processing circuit 128 included in a central processing unit (CPU) 126. The graphics for CGB are created from blocks of pixels known as characters. Characters are typically 8 pixels wide and 8 pixels high (or 8 pixels wide and 16 pixels high). Characters can be used to represent both background and object data. Backgrounds are groups of characters laid out like tiles to create the environment or background of a game. Objects are groups of character data that are used to represent the main game character and other moving objects that overlay the background in a game. Objects are sometimes referred to as sprites.
CPU 126 further includes a CPU core 130 that is connected to an internal read only memory (ROM) 132 and an internal random access memory (RAM) 134. Internal RAM 134 is used as a work memory of CPU core 130. CPU 126 further includes a basic oscillator 136. Basic oscillator 136 is formed of, for example, a quartz oscillator, and supplies an oscillating signal to a programmable frequency divider 138. Programmable frequency divider 138 divides the oscillating signal from basic oscillator 136 in accordance with frequency division data from CPU core 130, and supplies a divided signal as a clock of CPU core 130.
A connector 140 is connected to CPU 126 by an appropriate bus. Game cartridge 112 is selectively attachable to connector 140. Game cartridge 112 is preferably in the form of a replaceable memory cartridge insertable into game cartridge slot 118 of the CGB. Game cartridge 112 may comprise a plastic housing that encases a printed circuit board. The printed circuit board has a connector defining a number of electrical contacts. When game cartridge 112 is inserted into game cartridge slot 118 of the CGB, the cartridge electrical contacts mate with corresponding “edge connector” electrical contacts within game system 110. This action electrically connects the printed circuit board contained within the plastic housing to the electronics within game system 110. In this example, the printed circuit board of game cartridge 112 at least includes a read-only memory (ROM) 142 and a read/write memory (e.g., SRAM) 146. ROM 142 stores instructions and other information pertaining to a particular video game. The ROM for one game cartridge 112 may, for example, contain instructions and other information for an adventure game while the ROM of another game cartridge 112 may contain instructions and other information for a car race game, an educational game, etc. To play a game, a user of game system 110 need only plug the appropriate game cartridge into game cartridge slot 118 of the CGB—thereby connecting the cartridge's ROM 142 (and any other circuitry it may contain) to the CGB. This enables the CGB circuitry to access information contained within ROM 142 (and read/write memory 146), which information controls the game system to play the appropriate video game by displaying images and reproducing sound as specified under control of the ROM game program information. Read/write memory 146 is used to store data such as game backup data.
CPU 126 is supplied with operation signals from operating keys 148a-148e. Operating key 148a is used, among other things, to move a game character displayed on color LCD 116 in four directions, that is, upward, downward, right and left. Operating key 148b is a select key that is used for, for example, game mode selection and the like. Operating key 148c is a start key that is used to start playing the game or to temporarily stop the progress of the game. Operating keys 148d, 148e are push-button switches. By pushing operating keys 148d, 148e, it is possible to cause various motions of the game characters displayed on color LCD 116, for example, a weapon use, a jump and the like. Operating keys 148a-148e are disposed in a forward surface of the CGB as shown in FIG. 1B. A key matrix (not shown) is provided for sending CPU 126 the operation signals from operating keys 148a-148e as controller data.
Batteries (not shown) (e.g., 2 AA batteries) provide power for game system 110. A power indicator LED 119 (see FIG. 1B) may dim as the batteries lose their charge, thereby providing a visual indication to the user that new batteries are needed.
In accordance with the game program, character data supplied from game cartridge 112 and the controller data from operating keys 148a-148e, CPU 126 executes data processing and writes display data into a display RAM 152, using an extended RAM 150 when necessary. The display RAM 152 has two banks, that is, a first bank and a second bank, and has, as a whole, a storage area that is greater than the display area of color LCD 116, thereby enabling a scrolling display upward and downward and/or rightward and leftward on the screen of color LCD 116. As a result of the data processing by CPU 126, sound signals to be output are adjusted in level by volume control 154 and amplifier 156, and then outputted to a speaker 158 and/or an earphone jack 160. Sound signals output from speaker 158 and/or earphone jack 160 include game sound effects, voices and music.
Generally speaking, to use the CGB, a user selects a game cartridge 112 containing a desired video game, and inserts that game cartridge into game cartridge slot 118 of the CGB, thereby electrically connecting ROM 142 and other cartridge electronics to the CGB. The user then operates a power switch 121 (see FIG. 1B) to turn on the CGB and operates operating keys 148a-148e to control video game play. For example, depressing operating key 148c may cause the video game to start playing. Actuating operating key 148a may cause animated characters to move on color LCD 116 in controllably different directions.
It is of course desirable to use new and more powerful system components (e.g., more powerful processors, faster memory, more memory, etc.) in order to improve the system capabilities and provide an even more fascinating gaming experience. However, because users may have already invested time and money into existing game systems, it is also very desirable to maintain compatibility with existing game cartridges. Thus, users upgrading to the new and more powerful game systems can continue to use game cartridges that have been purchased for use with prior generations of game systems. In addition, these users can play new games that take advantage of the improved capabilities of the game system.
The hand-held display system for playing video games described herein includes a housing grippable by a user's hands, a liquid crystal display viewable by the user gripping the housing, input devices operable by the user when the user grips the housing, and a connector for, in use, operatively connecting to portable storage media storing video game programs for the video games. The hand-held display system further includes first processing circuitry for processing video game programs having a first program specification and second processing circuitry for processing video game programs having a second program specification. In one particular example implementation, the portable storage media are in the form of cartridges housing a semiconductor memory.
This hand-held display system described above and in greater detail below affords many features and advantages including, but not limited to:                high-power (e.g., 32-bit) first processing circuitry that expands computational abilities and data processing features to permit more interesting games to be played,        lower power (e.g., 8-bit) second processing circuitry to maintain compatibility with existing game cartridges so that players can continue to play and enjoy games developed for earlier generations of game systems,        widescreen and non-widescreen display formats on the liquid crystal display,        cartridge type detection circuitry to detect the cartridge type,        the input devices include easily accessible shoulder buttons at the upper corners of the portable game system housing to expand the variety of possible operations,        multi-player (up to four) game playing, even if only one of the portable game systems has a game cartridge inserted therein.        
These and many other features and advantages will be better and more completely understood by referring to the following detailed description of example embodiments in conjunction with the drawings.